A European research team has published the results of a 30-year study of an extraordinary hypergiant star. They have found that the surface temperature of the super-luminous star HR 8752 increased by about 3000 degrees in ...

(Phys.org)—Ten billion years ago or so, at least according to the current picture, the youthful universe began to produce an abundance of new stars. The very first ones appeared in the young cosmos after only a few hundred ...

It is well known that plant growth patterns are influenced by a variety of stimuli, gravity being one amongst many. On Earth plant roots exhibit characteristic behaviours called 'waving' and 'skewing', which were thought ...

ESA joined international delegates in Doha, Qatar, to discuss how satellite observations show our planet's most sensitive areas reacting to climate change – and how this information is useful to the people living there.

A new approach to invisibility cloaking may one day be used at sea to shield floating objects – such as oil rigs and ships – from rough waves. Unlike most other cloaking techniques that rely on transformation optics, ...

(Phys.org)—Researchers from Stanford University and Princeton suggest in a paper they've had published in the journal Science that magnetic fields associated with some black holes may be strong enough to cause thick accretion ...

Gravitation

Gravitation is a natural phenomenon by which objects with mass attract one another. In everyday life, gravitation is most commonly thought of as the agency which lends weight to objects with mass. Gravitation compels dispersed matter to coalesce, thus accounting for the existence of the Earth, the Sun, and most of the macroscopic objects in the universe. It is responsible for keeping the Earth and the other planets in their orbits around the Sun; for keeping the Moon in its orbit around the Earth; for the formation of tides; for convection, by which fluid flow occurs under the influence of a temperature gradient and gravity; for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena observed on Earth. Modern physics describes gravitation using the general theory of relativity, in which gravitation is a consequence of the curvature of spacetime which governs the motion of inertial objects. The simpler Newton's law of universal gravitation provides an accurate approximation for most calculations.

The terms gravitation and gravity are mostly interchangeable in everyday use, but a distinction is made in scientific circles. "Gravitation" is a general term describing the phenomenon by which bodies with mass are attracted to one another, while "gravity" refers specifically to the net force exerted by the Earth on objects in its vicinity as well as by other factors, such as the Earth's rotation.